Conventionally, Fe-based materials are used for electrical/electronic equipment, and recently Cu-based materials having excellent electricity and heat conductivity such as phosphor bronze, tombac, brass, Corson alloy, and the like have been widely used. As electrical/electronic equipment have become smaller, lighter in weight, and been more densely integrated in recent years, the Cu-based materials for electrical/electronic equipment need to improve strength, conductivity, stress relaxation resistance property, bending workability, plating property, press formability, heat resistance, and the like.
The Corson alloy, in which Ni and Si are added to Cu to precipitate a Ni—Si-based compound, is a Cu—Ni—Si-based alloy having excellent strength. For example, CDA70250 alloy registered on CDA (Copper Development Association) is commercially available.
Another Cu—Ni—Si-based alloy, in which a distribution state of a Ni—Si-based compound is designed to improve properties thereof, has been proposed (refer to Japanese Patent Publication Laid-Open Nos. 2005-298920 and 2001-49369).
However, the CDA70250 alloy and the Corson alloys disclosed in Japanese Patent Publication Laid-Open Nos. 2005-298920 and 2001-49369 fail to fully satisfy properties required for electrical/electronic equipment, and especially, do not provide sufficient plating property, press formability, and heat resistance.